RHEL5 is out and from memory it has a proper version of MP2 (somebody like to confirm whether you can just upgrade from 4 to 5?)
To answer my own question - yes you can upgrade:
http://www.redhat.com/rhel/moving/ although I don't know what the process is.RHEL5 comes with mod_perl 2.0.2, perl 5.8.8 and apache 2.2.3 so it's *nearly* up to date!
Anybody tried RHEL5 and like to comment on whether the perl performance is better than with RHEL4?
Carl